In the oil and gas industry, devices are often run into wells on lengths of flexible metallic hollow tubing which may stored coiled on a spool; the tubing is thus known as coiled tubing. Individual lengths of coiled tubing, which may be hundred of metres long, are joined by means of appropriate in-line connectors that fit and seal within the ends of the lengths. Coiled tubing is normally formed from strip rolled into a cylindrical form and then welded. As noted above, the tubing is then coiled for storage and transport. Thus the tubing forming operation, and subsequent handling and coiling of the tubing, normally results in the tubing featuring a degree of ovality and residual bend. Furthermore, the internal diameter of tubing formed from strip includes an axial weld seam. Accordingly, to prepare the end of a tubing length to receive a connector, particularly a connector featuring an elastomer seal, it is normal practice to ream the tubing end using a tool such as the applicant's Internal Combination Reamer System (ICRS) unit. This is a hand operated, self-aligning unit that prepares coiled tubing to accept the applicant's Elastomer Sealed Inline Connector. The ICRS tool features a two-part sleeve, one part of the sleeve for location over the end of the tubing and being fixed to the tubing using grub screws, and the other part of the sleeve providing mounting for a shaft extending into the sleeve. A reamer or other cutter is mounted on the end of the shaft within the sleeve, while a handle for rotating the reamer is provided on the other end of the shaft. An Acme thread couples the parts of the sleeve, such that relative rotation of the parts advances the reamer into the tubing on which the sleeve is mounted. Thus, using the handle to rotate the shaft and turn the reamer while rotating the sleeve parts to feed the reamer through the tubing, a skilled operator may use the ICRS tool to ream the end of a tubing length to produce an acceptable seal bore finish on the tubing internal diameter, ready to receive a connector. However, this is a time-consuming operation. For example, reaming a 2⅞″ (7.3 cm) outside diameter 0.190″ (0.48 cm) wall thickness coiled tubing to a depth of 7″ (17.8 cm) will typically take around four hours. Furthermore, inexperienced or unskilled operators often have difficulty in achieving the level of finish necessary to achieve a fluid-tight seal between the tubing and a connector, and furthermore will often damage the reamer: one common problem is that the reamer is advanced too quickly into the tubing and when the reamer is rotated the reamer takes too big a “bite” of the tubing wall, which leads to a poor finish and damage to the reamer. It is also difficult to ream the larger sizes of coiled tubing, due to the torque required to turn the cutter.
It is among the objectives of embodiments of the invention to provide a reaming apparatus that obviates or mitigates at least some of these difficulties.